A lithography technique that promotes downscaling of a semiconductor device is an important process of generating a pattern among semiconductor manufacturing processes. In recent years, the circuit line width required for a semiconductor device is downscaled as the density of an LSI (Large-Scale Integration) becomes higher. A photomask used for forming such a downscaled circuit pattern is formed by using an electron-beam drawing technique. In the electron-beam drawing technique, a photomask is formed by irradiating electron beams to a mask blank to draw a mask pattern.
For example, there is a drawing device using multiple beams. A drawing device using multiple beams can irradiate more beams at one time than in a case of drawing with one electron beam and thus can improve the throughput. This type of multibeam drawing device shapes an electron beam emitted from an electron gun into multiple beams by using an aperture array having a plurality of holes, executes blanking control of the multiple beams, and downsizes and deflects beams that have not been shielded, by using an optical system to be irradiated to the mask blank.
The respective amounts of the multiple beams are individually controlled according to irradiation times. In this multibeam drawing device, a reduction in the beam irradiation times is demanded to further improve the throughput.